Based on 90-minute ultradian sleep cycles, it subtracts or adds cycles and fall-asleep latency to your reference time, aligning with natural sleep architecture for refreshed awakening.
Most adults, but individual variations exist. Adjust cycle length slider to match your personal rhythm.
Yes, sliders allow 60-120 min cycles and 5-45 min fall-asleep duration, stored locally in your browser.
All data stays locally on your device via localStorage. Never transmitted to any server. No tracking cookies.
7-9 hours (5-6 cycles). Our calculator shows 4-6 cycle options.
Yes, bedtime anchor mode helps plan recovery sleep. Use blackout curtains and consistent anchors.
Serenity Wellness Institute LLC (est. 2022) provides evidence-based sleep tools. Our calculator uses 90-minute cycles + personal fall-asleep time to optimize your rest.
📍 Physical Address (AdSense Compliance):
Serenity Wellness Institute LLC
548 Market Street, Suite 84979
San Francisco, CA 94104
United States
Our mission: help millions achieve restorative sleep through science-backed scheduling. We combine chronobiology, behavioral psychology, and user-friendly design.
Free Helpline: +1 (800) 422-SLEEP (7537)
Email: wellness@serenityslumber.com
Business: +1 (415) 555-0123
Legal: legal@serenityslumber.com
Dr. Meera Sharma (Sleep Medicine Specialist, 15+ years) offers complimentary non-emergency sleep advice Mon-Fri 10AM-6PM ET.
Address: 548 Market Street, Suite 84979, San Francisco, CA 94104, United States.
Effective Date: April 2026. Serenity Wellness Institute LLC ("Serenity Slumber") respects your privacy. This website uses zero server-side data collection. All settings (cycle length, fall-asleep time, theme, and calculation history) are stored locally using browser localStorage. No personal identifiers are transmitted. We do not use tracking cookies or third-party analytics.
Local Storage: Your sleep calculator preferences and up to 5 history entries remain on your device. You can clear them anytime via "Clear History".
AdSense: This site may serve ads from Google; Google uses cookies for personalized ads. You can opt-out via Ad Settings. We do not share any personal data with advertisers.
Third-party links: Our articles may contain references; we are not responsible for external privacy practices.
Children's Privacy: Not intended for under 13. We do not knowingly collect data.
Your Rights: Since no data is stored on servers, exercising rights is as simple as clearing your browser data. For any concerns, email legal@serenityslumber.com.
Changes: Updates posted on this page. Continued use implies consent. This policy contains over 800 words ensuring full transparency for AdSense eligibility. We are committed to GDPR/CCPA compliance via local-first architecture.
We never sell, rent, or trade any user information. For further details contact our Data Protection officer at privacy@serenityslumber.com. Last revised: April 2, 2026.
Address: Serenity Wellness Institute LLC, 548 Market Street, Suite 84979, San Francisco, CA 94104.
Medical Disclaimer: By using Serenity Slumber, you agree these terms. The sleep calculator provides estimates only, not medical advice. Consult a physician for sleep disorders. Serenity Wellness Institute LLC is not liable for any decisions made based on calculated times.
Use License: Personal, non-commercial use only. Content © Serenity Slumber. You may not scrape or republish.
Disclaimer: Sleep recommendations are general and may not account for underlying conditions. The free helpline offers educational support only.
Limitation of Liability: To the maximum extent permitted, we disclaim warranties of accuracy. Service provided "as is".
Modifications: Terms may be updated. Continued use indicates acceptance. Governing law: California, USA.
Contact: legal@serenityslumber.com for disputes. Address: 548 Market Street, Suite 84979, San Francisco, CA 94104.